
20220720: What If We Live in a Superdeterministic Universe?
 11:54: And that’s … impossible because if you trace the past lightcone of any two points in the observable universe back far enough they will overlap.


20220615: Can Wormholes Solve The Black Hole Information Paradox?
 02:24: ... amount of information hidden by a system  information not observable in the system’s gross properties. Black holes have huge entropy ...


20220420: Does the Universe Create Itself?
 16:10: ... the cosmic event horizon would have wavelength roughly the size of the observable universe. Unfortunately that makes it not very detectable without a ...
 17:39: ... fact  if you calculate the size of a black hole with the mass of our observable universe  adding together all the stars, dark matter, other black ...


20220323: Where Is The Center of The Universe?
 12:47: ... and that if you zoom out to many, many, many times larger than the observable universe, everything evens out ...


20220223: Are Cosmic Strings Cracks in the Universe?
 08:50: ... expanding universe stretched them up to the size of the observable universe. We actually expect multiple nucleation events in each ...


20220112: How To Simulate The Universe With DFT
 00:00: ... you used every particle in the observable universe to solve the schrodinger equation and do full quantum ...
 10:29: ... say that you can map from this charge density to the interesting observables  like the energy of the system, without having to go through the ...
 11:50: From there you can go ahead and calculate whatever observable you’re interested in.
 12:22: ...  the density distribution  could be mapped to all sorts of useful observables. ...


20211229: How to Find ALIEN Dyson Spheres
 12:08: There are hundreds of billions of galaxies in the observable universe.


20211117: Are Black Holes Actually Fuzzballs?
 01:14: ... no information from the matter that fell into a black hole should be observable on the surface  the socalled nohair theorem, which says that the only ...
 01:58: ... phrasing that black holes “have no hairs” to describe the absence of observable microstates in a black hole, which, on the surface, seems to contradict ...
 02:56: The nohair theorem says that there’s no information beyond charge, mass and spin that’s observable above the event horizon.


20211005: Why Magnetic Monopoles SHOULD Exist
 07:34: ... different sides of the string is exactly one wave cycle  which means no observable ...
 12:16: ... things far apart that there may be very few remaining in our entire observable ...


20210921: How Electron Spin Makes Matter Possible
 02:18: ... fact that all electrons, for example, are exactly the same  there is no observable change when you swap two electrons. Combining spin behavior and ...
 08:00: ... We’ll call it Psi. Psi gives the distribution of probabilities of some observable  for example, the location of the electron around the atom. Psi is ...
 09:45: ... Doesn’t that give us a way to “distinguish” the swap? Actually no  no observable property is changed by the swap. Remember, that we only “observe” the ...


20210818: How Vacuum Decay Would Destroy The Universe
 10:10: ... for a single such bubble to be likely to appear somewhere in our observable universe. So, somewhere between vaguely unlikely and ...


20210810: How to Communicate Across the Quantum Multiverse
 07:14: ... from linearity in the Schrodinger equation would add extra nonlinear observables to the wavefunction. The normal linear observables are things like ...
 07:50: ... In a single 1991 paper, Polchinski showed how Weinberg’s “nonlinear observables” would make it possible to achieve some pretty crazy science fiction ...


20210623: How Quantum Entanglement Creates Entropy
 12:35: ... becomes increasingly inaccessible, leaving only crude observable properties  for example, thermodynamic properties like ...


20210616: Can Space Be Infinitely Divided?
 06:02: ... we start to notice something. The photon is starting to produce an observable gravitational field. Even though photons are massless, if enclosed ...


20201104: Electroweak Theory and the Origin of the Fundamental Forces
 04:50: ... determines the probabilities of certain outcomes being measured for observables like particle position and ...
 05:18: ... however you like at any point in space and still get the same physical observables. ...


20201013: Do the Past and Future Exist?
 06:58: Our entire timeslice of our present is never observable in the present.
 09:04: ... the effect is tiny, but the “present” at the edge of the observable universe veers back and forth by a couple of centuries every time you ...


20200728: What is a Theory of Everything: Livestream
 00:00: ... to give a plug to my friend eric weinstein he has this idea of the observable verse in his theory i saw i think we should have a marketplace of ...


20200511: How Luminiferous Aether Led to Relativity
 09:02: ... quite a bit smaller than a single wavelength of light would produce observable shifts in the fringe pattern. And this is exactly the method that LIGO ...


20200331: What’s On The Other Side Of A Black Hole?
 13:01: ... instead causes quantum states to become correlated with macroscopic observables. The entanglement is dispersed through the environment, but in a coherent ...


20200316: How Do Quantum States Manifest In The Classical World?
 03:37: ... of other states. So again  why are only certain quantum states observable on large scales? The answer lies in ...
 13:22: ... the measurement problem it only tells us why certain quantum states are observable on macroscopic scales while Schroedinger Cat states  weird ...
 13:47: ... the framework of decoherence and these propagating pointer states. The observable qualities of reality  object positions, feline mortality statuses, even ...


20200303: Does Quantum Immortality Save Schrödinger's Cat?
 00:39: ... existing in many states at the same time, to having only one clear observable state at the moment of ...


20200211: Are Axions Dark Matter?
 12:47: ... 13.5 billion years it would be around 10^10^50 times the size of our observable universe. And that sounds about right. He then compares that to an ...
 15:20: ... that is itself large enough to fit all possible configurations of observable universe sized regions. The volume would want to be 10^10^123 (or 90) ...


20200203: Are there Infinite Versions of You?
 09:40: For our 46billion light year observable universe there are definitely no more than 2^10^123 possible unique configurations.
 09:52: As long as the greater universe has more than than that many observable universesized regions, one of them should be identical to this one.
 10:31: ... this may never be testable  we can measure the observable part of the universe to greater and greater precision and see if it has ...


20200127: Hacking the Nature of Reality
 00:43: ... mathematical description should depend only on observable quantities  in this case, the mysterious frequencies of light produced ...
 01:30: ... Neils Bohr passionately advocated it, insisting that matters are the observables  the measurable start and end points of an ...
 04:10: ... field theory of the internal nucleus, but rather by understanding the observables ...
 04:25: In this case the observables were the particles that entered and left the nucleus in a scattering experiment.
 12:56: ... takes Heisenberg’s old philosophy to the extreme  “only consider the observables” the amplituhedron doesn’t just eliminate the fiddly mechanics of quantum ...


20191118: Can You Observe a Typical Universe?
 00:45: ... Way is an ordinary galaxy among 100s of billions of galaxies in the observable ...
 05:45: All particles in the observable universe were packed together in a subatomicsized dot.
 08:33: For example a fluctuation the size of a galaxy is insanely more likely than one the size of our observable universe.


20191015: Loop Quantum Gravity Explained
 03:33: ... time, momentum, energy  mathematical expressions that represent the observable properties of the object or system that you’re trying to ...


20191007: Black Hole Harmonics
 02:14: ... – which intensify as the black holes approach merger, only becoming observable in the last fraction of a ...


20190930: How Many Universes Are There?
 00:24: ... it: the observable part of our universe is 93 billion light years across, and that’s just a ...
 12:51: But it still should NOT be surprising that we don’t see evidence of bubble collisions in our observable universe.


20190806: What Caused the Big Bang?
 00:43: ... being: why is matter and energy so smoothly spread out across the entire observable ...


20190725: Deciphering The Vast Scale of the Universe
 00:30: In fact there are surely more entire worlds in the observable universe than there are grains of sand on this one.


20190516: The Cosmic Dark Ages
 00:04: ... era. Somewhere between 10 and 1000 billion trillion stars fill the observable universe with light. But there was a time before the first star ...


20190403: The Edge of an Infinite Universe
 00:37: For example we have the “observable universe” – that patch that we can see, and beyond which light has not yet had time to reach us.
 00:57: Our observable universe is like a tiny patch of land in a vast plain.


20190207: Sound Waves from the Beginning of Time
 13:43: Well, the answer is it depends on what size you consider. For the entire observable universe?


20181121: 'Oumuamua Is Not Aliens
 07:42: But until someone does a proper calculation to show that tumbling must change in an observable way, this is not a serious argument.


20181025: Will We Ever Find Alien Life?
 16:40: ... belief or rather valuing the capacity of science to make concrete, observable predictions based on evidencebased models and that any interpretation ...


20181018: What are the Strings in String Theory?
 01:10: So surely there exists a deeper set of cogs and wheels, a theory that brings all observable phenomena into the same mechanical framework.


20181010: Computing a Universe Simulation
 03:34: ... that the maximum information content, the Bekenstein bound, of the observable universe is around 10 to the power of 120 bits based on its surface ...
 03:59: ... bound suggests that we could hold all of the information in the observable universe within a storage device smaller than the observable universe, ...
 05:13: ... informationally speaking, you could store the entire observable universe of nonradiation particles on the surface area of a black hole ...
 08:04: ... the energy of the system, we use the mass of the observable universe, around 10 to the power of 52 kilograms, and then apply good ...


20181003: How to Detect Extra Dimensions
 08:14: ... itself, which defines the threedimensional structure on which our observable universe exists, can actually expand into the extra fourth spatial ...
 10:49: There was no observable leakage of gravity into extra spatial dimensions, pretty much ruling this out as an explanation for dark energy.


20180920: Quantum Gravity and the Hardest Problem in Physics
 00:00: [MUSIC PLAYING] MATT O'DOWD: Between them, general relativity and quantum mechanics seem to describe all of observable reality.
 14:35: dabeste points out that it's important to emphasize that you're talking about the observable universe, not the entire universe.
 14:43: ... size of the storage device needed to store all of the information in the observable ...
 14:53: I said "observable" near the start of the episode.
 14:56: But I dropped that "observable" part a couple of times later on.


20180912: How Much Information is in the Universe?
 01:07: How much information does it take to describe the entire observable universe?
 05:04: ... observable universe has a surface area of 10 to the power of 120 to 10 to the power ...
 06:02: The observable universe contains something like 10 to the power of 80 protons.
 06:27: The cosmic microwave background has around 10 to the power of 89 photons across the observable universe.
 09:47: How large a black hole computer would you need in mass and radius to contain enough data to simulate the entire observable universe?
 15:24: ... reliably eliminate all of the 10 to the power of 80 protons in the observable universe, you need around 265 halflives, or 10 to the power 42 to 43 ...


20180823: How Will the Universe End?
 06:45: So in something like 10 to the power of 39 or 10 to the power 40 years, all protons in the observable universe will be gone.


20180725: Reversing Entropy with Maxwell's Demon
 01:31: ... physicsspeak that could produce the same observed set of macroscopic observables, or the same ...


20180718: The Misunderstood Nature of Entropy
 04:11: For a given set of largescale observable properties, every possible configuration of particles that could give those properties is equally likely.


20180711: Quantum Invariance & The Origin of The Standard Model
 02:49: The best we can do is make a measurement of physical observables, like position or momentum.
 02:54: The wave function can represent different observables and it determines the distribution of possible results of measurement of those observables.
 04:40: In fact, as long as you make the same shift across the entire wave function, all the observables are unchanged.
 05:56: That shouldn't change our probabilities for the positions of the particles, but what about observables besides positions?


20180620: The Black Hole Information Paradox
 08:11: ... that there are certain pairs of quantumobservable complimentary observables, like position and momentum, that can't both be perfectly measured at the ...


20180516: Noether's Theorem and The Symmetries of Reality
 07:45: ... phase of an oscillation in a quantum field by any amount, and the observable properties of that field, like its particles, don't ...


20180411: The Physics of Life (ft. It's Okay to be Smart & PBS Eons!)
 01:24: ... energy being concentrated in your cup of coffee or all the matter in the observable universe being crunched into an infinitely dense point are low ...


20180117: Horizon Radiation
 01:01: ... no information can travel or the cosmological horizon that limits the observable ...
 12:56: Extremely large quakes can set the entire star ringing, which is observable in its effect on the extremely regular flashes of its pulsar jet.


20171025: The Missing Mass Mystery
 00:18: ... PLAYING] Our astronomical surveys have revealed an observable universe full of hundreds of billions of galaxies, each of them with as ...
 00:41: When we extrapolate observations to the entire observable universe, we find a billion trillion suns worth of mass.


20170920: The Future of Space Telescopes
 11:19: The neutron star would be totally disrupted when it got very close to the black hole, producing a blast of observable radiation.


20170830: White Holes
 08:34: Even though this type of white hole isn't observable, some physicists have taken the description very seriously.


20170810: The OneElectron Universe
 10:59: ... we talked about the controversial evidence that many galaxies in the observable universe are drifting very slightly towards a point beyond the cosmic ...
 11:23: ... assuming it's caused by a gravitational influence beyond the edge of the observable universe, then yeah, it no longer exerts a force on ...


20170802: Dark Flow
 00:08: It may be that much of the matter in the cosmos is drifting due to the ancient gravitational pull of something outside the observable universe.
 05:07: But what if you could measure the effect from hundreds of clusters across the observable universe?
 07:50: ... the dark flow, because that flow seems to affect galaxies across the observable universe, or to two and a half billion light years at least, far beyond ...
 08:08: ... of a gravitational attraction towards something beyond the edge of the observable ...
 08:32: In the earliest instance of the Big Bang, the observable universe was compressed into a subatomic scale.
 08:58: ... horizon, there exists a region of much more stuff, a different bubble of observable universe with more galaxies, more clusters, more dark ...
 09:40: ... of a neighboring region of the greater universe, beyond the horizon of observable ...


20170405: Telescopes on the Moon
 01:51: ... it can see into near ultraviolet wavelengths and in the visible range observable within our ...


20170125: Why Quasars are so Awesome
 06:49: But when viewed from halfway across the observable universe, that is impossibly tiny.


20170111: The EM Drive: Fact or Fantasy?
 08:05: ... he argues demonstrates that such a medium can reproduce certain quantum observables, like the energy levels of the hydrogen ...


20161012: Black Holes from the Dawn of Time
 02:35: It's thought that these fluctuations originally formed when the entire observable universe was smaller than a single atom.


20160929: Life on Europa?
 09:57: ... first, the simplest observable difference between the predictions of a local hidden variable theory ...


20160921: Quantum Entanglement and the Great BohrEinstein Debate
 07:13: ... John Stewart Bell figured out a set of observable results, the socalled Bell inequalities, that we'd expect to see in the ...


20160622: Planck's Constant and The Origin of Quantum Mechanics
 00:15: You might not expect the quantum behavior of the microscopic to be observable on all scales of the universe, but it is.


20160615: The Strange Universe of Gravitational Lensing
 12:58: ... function gets so hopelessly mixed with those of other particles that its observable quantum behavior can't be ...


20160504: Will Starshot's Insterstellar Journey Succeed?
 10:40: So dark energy only has an observable effect when its density is at least comparable to the density of regular matter.


20160427: What Does Dark Energy Really Do?
 10:16: If positively curved, that would mean a finite but very, very large greater universe with a volume at least 250 times that of our observable universe.
 11:12: And even then, they don't cover the entire observable universe.


20160406: We Are Star Stuff
 12:56: Well, we can sort of answer that for two particles at opposite sides of the currently observable part of the universe.


20160330: Pulsar Starquakes Make Fast Radio Bursts? + Challenge Winners!
 04:55: That's the mass of all the protons and neutrons in the observable universe.
 05:11: ... the proton, and we get that there are 6 by 10 to the 79 protons in the observable universe, and just as many ...


20160323: How Cosmic Inflation Flattened the Universe
 00:49: The observable universe is impossibly huge.
 04:49: It goes like this start with a universe so crunched down that the entire currently observable part of it was all causally connected.


20160316: Why is the Earth Round and the Milky Way Flat?
 11:42: Our observable universe was a tiny speck in that volume.
 12:16: And at the moment of recombination, when the CMB was emitted, it was emitted by all of the observable universe and beyond at the same time.


20160309: Cosmic Microwave Background Challenge
 00:43: In the process, the distance that the average photon could travel went from not very far to greater than the length of the entire observable universe.
 02:10: ... those blobs evolve into are now 1,100 times further away, giving us an observable universe that's 93 billion light years ...
 03:24: ... need an estimate of the baryonic mass and volume of the observable universe, you'll need the redshift of the CMB, and the Thomson ...


20160302: What’s Wrong With the Big Bang Theory?
 01:00: And at that point, the entire observable universe was around the size of a grain of sand.
 04:05: And pack all of the galaxies in the entire observable universe into a space 10 to the power of minus 20th of the width of a proton.
 05:40: ... one patch to the next by at most one part in 100,000 across the entire observable ...
 07:16: So those edges shouldn't be in each other's observable universes, not then, not now.
 11:22: ... would be correct if you add the word "observable" before the word "universe." Everything that we can see to our cosmic ...
 11:57: So we restrict ourselves to talking about the size of the observable part of it.


20160224: Why the Big Bang Definitely Happened
 02:36: ... fact, with raw general relativity, we get that the entire observable universe was once compacted into an infinitesimal point, a singularity ...
 07:37: ... early age of 10 to the power minus 32 seconds, when the entire current observable universe was around the size of a grain of sand, give or ...


20160211: LIGO's First Detection of Gravitational Waves!
 03:44: It's expected that an observable merger of two black holes will happen only once every 10,000 years in any given galaxy.
 03:56: Advanced LIGO can feel the ripples produced by merging black holes through a volume of space equal to about 0.1% of the observable universe.


20151216: The Higgs Mechanism Explained
 03:40: ... the simplest is to say that while the photon can cross the entire observable universe without bumping into a single thing, the electron is never not ...
 09:05: ... merging super massive black holes should have temperatures raised by an observable amount by the gravitational ...


20151209: How to Build a Black Hole
 00:21: ... whose boundary curvature effectively removes the interior from our observable ...


20151028: Is The Alcubierre Warp Drive Possible?
 05:08: In fact, it would take significantly more negative energy than there is positive mass/energy in the entire observable universe.


20151015: 5 REAL Possibilities for Interstellar Travel
 02:30: And to do that with any liquid rocket fuel, you'd need a fuel tank larger than the observable universe.


20150930: What Happens At The Edge Of The Universe?
 01:04: In a previous episode, we talked about the size of what we call the observable universe.
 03:02: It's a boundary to the observable universe.
 04:40: Move to my left, and my observable universe moves with me.


20150225: How Do You Measure the Size of the Universe?
 00:52: So we're going to focus on the observable universe.
 01:31: And that's the radius of the observable universe.
 02:18: ... can expand at a variable rate, complicate how we measure the size of the observable ...
 05:13: So that's how we know that the observable universe is about 90 billion light years in diameter.


20150218: Is It Irrational to Believe in Aliens?
 05:39: ... or that intelligent aliens evolve, none of whom ever spread out in any observable way in the 10billionyear history of the ...
